It's very much like how in 2015-16 when Breath of the Wild was still only known as 'Zelda Wii U' and we knew next to nothing about the game other than it was in development for Wii U and it was open-world.
By this point, the Switch was still only known as 'NX'. And everyone and their grandmother assumed they were going to pull another 'Twilight Princess' where they release 'Zelda Wii U' on both Wii U AND NX. I even recall the Nintendo Direct in Nov 2015 where Reggie kept repeating "New Zelda for Wii U... for Wii U... for Wii U," and it was pointed out by multiple people "You didn't say it WASN'T for NX, Reggie!"
Sure enough, look what happened.
Either Pokemon or Prime 4 is going to be cross-gen. I'm sure of it. They're just waiting until that Switch 2 Direct on April 2nd to officially announce it. I'm leaning towards Metroid Prime 4 because that game I think benefits the most of getting an enhanced Switch 2 version and to be the game that serves as the definitive tech demo/demonstration of Switch 2's leap over Switch 1.
Pokemon will likely remain Switch 1 exclusive just because of how Game Freak and Pokemon Co. are stubborn with moving on to next gen hardware. (Black/White 2 released on the DS in 2012; Ultra Sun/Ultra Moon released on the 3DS in 2017. And they likely want to give Switch 1 one last true major exclusive before moving on to Switch 2.
Hardware Comparison Threads:
Current Thread
Switch 1 '25 vs DS '11, 3DS '17, and Wii '12
Older Threads:
PlayStation/Xbox/Switch: 2022 Edition
PlayStation/Xbox/Switch Hardware Battle: 2021 Edition!
PlayStation 4/Xbox One/Nintendo Switch: 2019 vs. 2020
PlayStation 4/Xbox One/Nintendo Switch: 2018 vs. 2019
PlayStation 4/Xbox One/Nintendo Switch: 2017 vs. 2018
PlayStation 4: 2015 vs. 2016 vs. 2017